This invention relates to a buckling beam test probe assembly, including a plurality of probe wire arrays each of which is adapted to a pattern of test pads of a microelectronic circuit.
Buckling beam probe contactors have been utilized for testing the electrical characteristics of integrated circuits connected to pads on a semiconductor chip. The probe wires of the probe assembly engage the pads to electrically connect the pads in parallel to the test apparatus. Limited force application is needed to prevent damage to the pads or the microelectronic circuit. Additionally, since the pads are located in close proximity, thin deflectable wires functioning as buckling beams must have their contact tips accurately positioned with respect to the pads to prevent shorts between circuits.
Buckling beam test probe contactors already proposed include a central support post which is designed to carry guide means for a plurality of buckling probe wires. The tips of these wires form a test pattern or array, and a plurality of such test patterns or arrays are arranged closely adjacent to each other to form a test head adapted to contact in parallel the pads of a complex microelectronic circuit. Each array contains a certain area in which there are no wire tips due to the presence of the central support post. Thus, if the pad pattern to be tested includes pads in that specific area, such pads cannot be tested in the same test operation but must be subject to a second test operation utilizing a modified test probe assembly. In this regard, reference is made to the U.S. applications Ser. No. 509,519 filed June 30, 1983, now U.S. Pat. No. 4,518,910, Ser. No. 279,128 filed June 30, 1981, now U.S. Pat. No. 4,506,215 and Ser. No. 278,950 filed June 30, 1981, now U.S. Pat. No. 4,554,506, all assigned to the assignee of the present invention.
It is also known to use a buckling beam test probe assembly which consists of a plurality of test probe wires the tips of which form a matrix (U.S. Pat. No. 3,806,801). These wires are supported by a solid frame which does not allow the arrangement of a plurality of such probe arrays in close proximity to each other.
The invention solves the problem of contacting in one test operation a plurality of closely adjacent test pad patterns of a complex microelectronic circuit where in each pattern the area in which there are no test probe wires due to the presence of wire guide support means is reduced to a minimum.
The buckling beam test probe assembly according to the invention has the advantage of allowing an easy and time-saving mounting of a large plurality of buckling beam arrays arranged in quads each containing, for example, 25 test probe arrays. These arrays are arranged in close proximity to each other and contain very limited areas which are not occupiable by test wire tips in accordance with the pattern of pads being contacted.